Recovery
Definition
The fraction of analyte that survives the extraction and clean-up workflow, measured by spiking a known amount of analyte into a blank matrix, running the full method and back-calculating. The accepted forensic window is 80 to 120 percent. A recovery of 45 percent is not necessarily wrong, but the method must correct for it through internal-standard normalisation, and the recovery figure must be on the validation report.
Related terms
- Bracketing Standards
- Calibration standards or quality control samples injected before, during and after a batch of case samples. They track instrument drift through the...
- Calibration Curve
- In RIA, a set of standards containing known concentrations of unlabelled analyte that are run alongside test samples. Bound radioactivity is measured...
- Certified Reference Material (CRM)
- A sample with one or more analyte concentrations established by an accredited body and traceable to a national metrology institute. NIST SRM...
- Extraction
- The first step in sample preparation. The analyte is pulled out of its original matrix (blood, urine, viscera, soil, paint chip) into...
- Internal Standard (IS)
- A compound chemically near-identical to the analyte, often a deuterated isotopologue (d3-morphine, d5-EDDP, d5-alprazolam, pyrene-d10), spiked into every sample at a known...
- Limit of Detection (LOD) and Limit of Quantitation (LOQ)
- LOD is the lowest concentration the instrument can reliably distinguish from blank, defined as three times the standard deviation of the blank...
Explained in
- Sample Preparation, Purification and Instrument CalibrationThe fraction of analyte that survives the extraction and clean-up workflow, measured by spiking a known amount of analyte into a blank matrix, running the full...